1package eu.siacs.conversations.utils;
2
3import java.math.BigInteger;
4import java.nio.charset.Charset;
5import java.security.MessageDigest;
6import java.security.NoSuchAlgorithmException;
7import java.security.SecureRandom;
8import java.util.Random;
9
10import eu.siacs.conversations.entities.Account;
11
12import android.util.Base64;
13
14public class CryptoHelper {
15 final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
16 final protected static char[] vowels = "aeiou".toCharArray();
17 final protected static char[] consonants = "bcdfghjklmnpqrstvwxyz"
18 .toCharArray();
19
20 public static String bytesToHex(byte[] bytes) {
21 char[] hexChars = new char[bytes.length * 2];
22 for (int j = 0; j < bytes.length; j++) {
23 int v = bytes[j] & 0xFF;
24 hexChars[j * 2] = hexArray[v >>> 4];
25 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
26 }
27 return new String(hexChars).toLowerCase();
28 }
29
30 public static String saslPlain(String username, String password) {
31 String sasl = '\u0000' + username + '\u0000' + password;
32 return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()),
33 Base64.NO_WRAP);
34 }
35
36 private static byte[] concatenateByteArrays(byte[] a, byte[] b) {
37 byte[] result = new byte[a.length + b.length];
38 System.arraycopy(a, 0, result, 0, a.length);
39 System.arraycopy(b, 0, result, a.length, b.length);
40 return result;
41 }
42
43 public static String saslDigestMd5(Account account, String challenge) {
44 try {
45 Random random = new SecureRandom();
46 String[] challengeParts = new String(Base64.decode(challenge,
47 Base64.DEFAULT)).split(",");
48 String nonce = "";
49 for (int i = 0; i < challengeParts.length; ++i) {
50 String[] parts = challengeParts[i].split("=");
51 if (parts[0].equals("nonce")) {
52 nonce = parts[1].replace("\"", "");
53 } else if (parts[0].equals("rspauth")) {
54 return null;
55 }
56 }
57 String digestUri = "xmpp/"+account.getServer();
58 String nonceCount = "00000001";
59 String x = account.getUsername() + ":" + account.getServer() + ":"
60 + account.getPassword();
61 MessageDigest md = MessageDigest.getInstance("MD5");
62 byte[] y = md
63 .digest(x.getBytes(Charset.defaultCharset()));
64 String cNonce = new BigInteger(100, random).toString(32);
65 byte[] a1 = concatenateByteArrays(y,(":"+nonce+":"+cNonce).getBytes(Charset.defaultCharset()));
66 String a2 = "AUTHENTICATE:"+digestUri;
67 String ha1 = bytesToHex(md.digest(a1));
68 String ha2 = bytesToHex(md.digest(a2.getBytes(Charset
69 .defaultCharset())));
70 String kd = ha1 + ":" + nonce + ":"+nonceCount+":" + cNonce + ":auth:"
71 + ha2;
72 String response = bytesToHex(md.digest(kd.getBytes(Charset
73 .defaultCharset())));
74 String saslString = "username=\"" + account.getUsername()
75 + "\",realm=\"" + account.getServer() + "\",nonce=\""
76 + nonce + "\",cnonce=\"" + cNonce
77 + "\",nc="+nonceCount+",qop=auth,digest-uri=\""+digestUri+"\",response=" + response
78 + ",charset=utf-8";
79 return Base64.encodeToString(
80 saslString.getBytes(Charset.defaultCharset()),
81 Base64.NO_WRAP);
82 } catch (NoSuchAlgorithmException e) {
83 return null;
84 }
85 }
86
87 public static String randomMucName() {
88 Random random = new SecureRandom();
89 return randomWord(3, random) + "." + randomWord(7, random);
90 }
91
92 protected static String randomWord(int lenght, Random random) {
93 StringBuilder builder = new StringBuilder(lenght);
94 for (int i = 0; i < lenght; ++i) {
95 if (i % 2 == 0) {
96 builder.append(consonants[random.nextInt(consonants.length)]);
97 } else {
98 builder.append(vowels[random.nextInt(vowels.length)]);
99 }
100 }
101 return builder.toString();
102 }
103}